[7u] RFR: JDK-8274407: (tz) Update Timezone Data to 2021c

[Dmitry Cherepanov]

JBS: https://bugs.openjdk.java.net/browse/JDK-8274407
Webrev: http://cr.openjdk.java.net/~dcherepanov/openjdk7u/8274407/webrev.01/

Applies clean after path shuffling. Skipped tests as no copy of the data in the test folder, and changes in ZoneInfoFile.java aren't applicable as JDK-8011172 introduced in 8. Relevant tests passed.

Thanks,

Dmitry